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Podcasts

The Literate Brain

Pélagie M. Beeson, PhD, Professor and Head of Speech, Language and Hearing Science

Written language represents a relatively recent cultural invention, and unlike the development of spoken language, literacy requires explicit and prolonged instruction. How is this accomplished? Do unique regions of the brain develop in support of reading and spelling, or are these skills dependent upon brain regions involved in other perceptual and cognitive processes? By studying disorders that arise following brain damage in previously literate adults, and by using brain imaging techniques to examine neural activity as healthy individuals engage in reading and spelling, a new understanding of the brain is being revealed. Further clarification comes from rehabilitation research that promotes the return of written language skills and provides a view of the brain’s plasticity.

The Ancestors in Our Brains

The human brain retains ancestral neural circuits that support behaviors geared toward satisfying basic biological needs. Superimposed on these core circuits are newly evolved structures that specialize in complex computations. These specializations convey flexibility to the brain and the ability to distill information into abstract thought. The ancient molecules and core circuits that make us social and emotional beings interface harmoniously with the newly evolved structures that make us thinkers and inventors of technology.

More Perfect Than We Think

William Bialek, PhD, John Archibald Wheeler/Battelle Professor in Physics, Princeton University

From its ability to appreciate beauty, to the reassembly of distant childhood memories, to our almost unthinking ability to respond to the unexpected, is our brain really "doing a good job" at solving the problems we confront as we move through the world? Has evolution granted us a rich inheritance of tools, or saddled us with artifacts of a distant past, limiting our ability to solve new problems? Many other animals, from insects to our fellow primates, do many equally remarkable things, but several examples will be presented allowing us to see how the human brain solves problems in an essentially perfect way — no machine operating under the same physical constraints could do better. Examining what is common among the problems that the brain is good at solving begins to suggest a more general principle that may be at work.

The last 20 years have been marked by an astonishing growth in our knowledge about the molecules that make up living things. And among those molecules, none has attracted more attention than DNA. The DNA code of hundreds of life forms has been sequenced, and this code contains not only information needed to assemble all proteins; a myriad of bit and pieces of DNA are also involved in controlling when proteins are built and destroyed. It is thus not surprising that DNA has been called the software of life, but the metaphor breaks down when we look more closely. Contrary to any reputable software, small, random "errors" are introduced in the code each time DNA is copied in order to be transmitted to the next generation. Most often, these changes have no effect whatsoever. Almost all the remaining changes are deleterious and are most likely the cause of the many diseases that affect many human beings at some point in their lives. But a small portion of these random "errors" allow those who carry them to better adapt to the environment in which they live. And the fast and slow accumulation of those favorable "errors" is what ultimately gave rise to the immensely successful history of life in the planet. Two indispensable conclusions arise: first, disease is often caused by the same mechanism, random mutation, that allowed us to become conscious beings and, therefore, those of us who are healthy and can pursue happiness have a basic biological and ethical debt towards those who are not; second, the massive changes that we are introducing into the environment are making many of us sick simply because our ancestors never saw them and thus, never "adopted the right genes" for them. Contrary to all other species that ever existed, therefore, we are increasingly putting our future as a species in our own hands.

The Genesis of the 1918 Spanish Influenza Pandemic

Michael Worobey, Professor, Ecology and Evolutionary Biology, The University of Arizona

The Spanish influenza pandemic of 1918 was the most intense outbreak of disease in human history. It killed upwards of 50 million people (most in a six-week period) casting a long shadow of fear and mystery: nearly a century later, scientists have been unable to explain why, unlike all other influenza outbreaks, it killed young adults in huge numbers. I will describe how analyses of large numbers of influenza virus genomes are revealing the pathway traveled by the genes of this virus before it exploded in 1918. What emerges is a surprising tale with many players and plot lines, in which echoes of prior pandemics, imprinted in the immune responses of those alive in 1918, set the stage for the catastrophe. I will also discuss how resolving the mysteries of 1918 could help to prevent future pandemics and to control seasonal influenza, which quietly kills millions more every decade.

Genomics and the Complexity of Life

Michael W. Nachman, Professor, Ecology and Evolutionary Biology, The University of Arizona

What determines the complexity of life? Darwin described how evolution produced “endless forms most beautiful”, yet he was unaware of genetics and the laws of inheritance. Our genomes provide the ultimate record of evolution, and evolution explains many fascinating aspects of our genomes. How do changes in the genome allow organisms to adapt to their environment? How do changes in the genome produce new species? Why do worms and humans have about the same number of genes? This lecture will explore how genomics has deepened our understanding of evolution in ways Darwin never could have imagined.

The 9 Billion-People Question

Rod A. Wing, Bud Antle Endowed Chair, School of Plant Sciences and Director, Arizona Genomics Institute, The University of Arizona

The world’s population will grow to more than 9 billion in less than 40 years. How can farmers grow enough food to feed this population in a more sustainable and environmentally friendly way? Research is now underway to create the next generation of green revolution crops - the so called “green super crops” where “super” means a doubling or tripling of yields, and “green” means a reduction in the use of water, fertilizer, and pesticides etc. The 9 billion-people question (9BPQ) is one of the world’s most pressing issues of our time. Our society must realistically solve this question within the next 25 years if we are to be able to supply farmers with the seeds required to feed the future. This lecture will explore the many facets of how to feed the world and will propose a bold solution to help solve the 9BPQ.

Epigenetics: Why DNA Is Not Our Destiny

Donata Vercelli, MD, Professor, Cellular and Molecular Medicine; Director, Arizona Center for the Biology of Complex Diseases, The University of Arizona

Two twin sisters, one with and one without asthma. Two genetically identical mice, one black and lean, the other yellow and obese. Two human cells, one from the brain and the other from the skin: they look and act different, but they have the same DNA sequence. All of this is the work of epigenetics. Much emphasis has been placed on DNA and genes as repositories of the code designed to transmit information and dictate biological programs. However, developmental trajectories and responses to environmental cues are – and need to be – highly plastic. This plasticity is made possible by epigenetic mechanisms that enhance or silence gene expression at the right time in the right environmental context but do not change the DNA sequence. Thus the code inscribed in our DNA is necessary but not sufficient to recapitulate our biological identity and determine our biological destiny. This lecture will explore how understanding epigenetics will advance our understanding of human biology and disease.

Genomics Tomorrow

This panel discussion will bring together this series' five esteemed presenters to address the complex and varied issues associated with genomics research and its potential impact on individuals and society. At the discussion's core will be the questions of mankind's role and responsibilities in choosing to "modify" nature. Topics will include: the risks and rewards associated the new norms of pre-natal genetic screening; the impact of readily available low-cost genetic profiling; global opportunities posed by genetically modified plants and organisms; and the potentials of a greatly expanded knowledge-base of infectious diseases and their treatments. The discussion will be moderated by College of Science Dean Joaquin Ruiz and audiences will be able to submit questions in advance for panel members' consideration.

Can We, and What If We Do?

Shane C. Burgess, Dean, College of Agriculture and Life Sciences, University of Arizona
For most of human history, what we today consider a "reasonable life span" was a significant achievement for the average human. This remains the case in many parts of the world, but for westerners in particular, the magic age "100" is becoming a milestone to which many now realistically aspire. Our science has allowed us to immortalize cells and is giving us pointers to achieving much longer life spans. Medicine and nutrition are also making rapid progress, and in many cases what were terminal diseases are becoming treatable inconveniences. But if being alive well beyond 100 years is possible, is it really "living"? What if we haven't planned to live that long; can we afford it? How will so many older citizens change our society? So, can we live beyond 100? The increasing numbers of centenarians affirm that the answer is "yes," but what are these special people made of and how can we learn from them?